1. Field of the Invention
This invention relates to a camera having an image memory for storing still image information.
2. Description of the Related Art
Techniques of introducing the image memory into the photographic camera have already been known. Yet, some unfavorable results have occurred as follows.
For example, Japanese Laid-Open Patent Application No. Sho 62-9289 discloses a camera of this kind in which, to shoot an object on action by the solid state image pickup element, its moving image is displayed on a monitor. When a shutter switch is pushed down, a still image is stored in a semiconductor memory. And, what picture has been taken and stored can be reviewed by reproduction on the monitor.
However, such a conventional camera had a drawback in that, if the shutter switch or release button was pushed at a time during the display of the preceding still image, because the next frame of an object to be shot was not monitored, the photographer failed to choose his desired target area. This would result also in a disadvantage of putting unnecessary still images into the memory.
Also in the conventional camera of this kind, each time a shot was taken, it was at a consecutive address to the last used one in the image memory that its still image information was stored. To read the image information out of the image memory, a similar way was adopted in the address sequencing. Hence, no particular measure was taken for control on the address sequencing in reading after the address for the "oldest" (or "newest") shot image has been reached.
As a result, when reading the memory reproduction circulated from the "oldest" shot abruptly to the "newest" one, or vice versa. Thus, the order in which the images had been shot became uncertain.
Further, the use of such a control by successive increments or decrements of all the addresses in reading the image information from the image memory led to allow even those storage areas which were not yet used for shooting to be accessed. Thus, still another drawback was seen in that the blank frames of no meaning were displayed.
It is also known to provide a conventional camera of this kind constructed by inserting a half mirror into the photographic optical system for the silver halide camera. The object image bearing beam is split off by the half mirror into two parts, one of which is directed to the solid state image pickup element. Hence, the same object image is recorded not only on the photographic film but on a semiconductor memory or like image memory device. And, after the recording is complete, the still image in the memory can be reproduced on the display. Yet, even after the camera is reloaded with new film, those still images which were recorded along with the old roll of film eventually find their reproduction on display. Therefore, this camera had a problem that it became uncertain that the reproduced image in question might be assigned to one or the other of the old and new rolls of film.
Another example of the conventional camera of this kind is disclosed in Japanese Laid-Open Patent Application No. Sho 57-78281, where when the release button is half pushed down for the first time, a moving image is displayed; when half pushed down for the second time, a still image is displayed; when half pushed down, the image memory gives off a stored image on the display; as long as an access button is pushed down, all the stored images in the memory are successively displayed; and when the release button is fully pushed down, the stored image under display is replaced by a new one. Since selection of the modes thus relied on recycling of depression of the release button to the half stroke, after the release button had once been pushed to the half stroke, the preceding viewed image continued being displayed until the button was further pushed to the full stroke, whereby much electrical energy was consumed. Another problem was that what mode is selectively set by how many times the release button has been pushed to the half stroke was very difficult for the user to foresee.
Also, in the conventional camera of this kind, for control of the zoom ratio of the motorized zoom lens, there is a wide-angle/telephoto selection switch dedicated solely to this purpose. Meanwhile, apart from this, another selection switch was provided for reading the information of one of the exposed images out of the image memory to display it. Hence the manual actuators on the camera housing became many in number. This involved errors in manipulation and eroded good manageability. Even for the designer, it provided layout difficulty.